//------------------------------------------------------------------------------
// <copyright file="BaseProcessor.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>  
// <owner current="true" primary="true">Microsoft</owner>                                                              
//------------------------------------------------------------------------------

namespace System.Xml.Schema {

    using System.Collections;
    using System.Text; 
    using System.Diagnostics;

    internal class BaseProcessor {
        XmlNameTable nameTable;
        SchemaNames schemaNames; 
        ValidationEventHandler eventHandler;
        XmlSchemaCompilationSettings compilationSettings; 
        int errorCount = 0;
        string NsXml;

        public BaseProcessor(XmlNameTable nameTable, SchemaNames schemaNames, ValidationEventHandler eventHandler)
            : this(nameTable, schemaNames, eventHandler, new XmlSchemaCompilationSettings()) {} //Use the default for XmlSchemaCollection

        public BaseProcessor(XmlNameTable nameTable, SchemaNames schemaNames, ValidationEventHandler eventHandler, XmlSchemaCompilationSettings compilationSettings) {
            Debug.Assert(nameTable != null);
            this.nameTable = nameTable;
            this.schemaNames = schemaNames;
            this.eventHandler = eventHandler;
            this.compilationSettings = compilationSettings;
            NsXml = nameTable.Add(XmlReservedNs.NsXml);
        }

        protected XmlNameTable NameTable {
            get { return nameTable; }
        }

        protected SchemaNames SchemaNames {
            get { 
                if (schemaNames == null) {
                    schemaNames = new SchemaNames(nameTable);
                }
                return schemaNames; 
            }
        }

        protected ValidationEventHandler EventHandler {
            get { return eventHandler; }
        }

        protected XmlSchemaCompilationSettings CompilationSettings {
            get { return compilationSettings; }
        }

        protected bool HasErrors {
            get { return errorCount != 0; }
        }

        protected void AddToTable(XmlSchemaObjectTable table, XmlQualifiedName qname, XmlSchemaObject item) {
            if (qname.Name.Length == 0) {
                return;
            }
            XmlSchemaObject existingObject = (XmlSchemaObject)table[qname];
            
            if (existingObject != null) {
                if (existingObject == item) { 
                    return;
                }
                string code = Res.Sch_DupGlobalElement; 
                if (item is XmlSchemaAttributeGroup) {
                    string ns = nameTable.Add(qname.Namespace);
                    if (Ref.Equal(ns, NsXml)) { //Check for xml namespace
                        XmlSchema schemaForXmlNS = Preprocessor.GetBuildInSchema();
                        XmlSchemaObject builtInAttributeGroup = schemaForXmlNS.AttributeGroups[qname];
                        if ((object)existingObject == (object)builtInAttributeGroup) {
                            table.Insert(qname, item);
                            return;
                        }
                        else if ((object)item == (object)builtInAttributeGroup) { //trying to overwrite customer's component with built-in, ignore built-in
                            return;
                        }
                    }
                    else if (IsValidAttributeGroupRedefine(existingObject, item, table)){ //check for redefines
                        return;
                    }
                    code = Res.Sch_DupAttributeGroup;
                } 
                else if (item is XmlSchemaAttribute) {
                    string ns = nameTable.Add(qname.Namespace);
                    if (Ref.Equal(ns, NsXml)) {
                        XmlSchema schemaForXmlNS = Preprocessor.GetBuildInSchema();
                        XmlSchemaObject builtInAttribute = schemaForXmlNS.Attributes[qname];
                        if ((object)existingObject == (object)builtInAttribute) { //replace built-in one
                            table.Insert(qname, item);
                            return;
                        }
                        else if ((object)item == (object)builtInAttribute) { //trying to overwrite customer's component with built-in, ignore built-in
                            return;
                        }
                    }
                    code = Res.Sch_DupGlobalAttribute;
                } 
                else if (item is XmlSchemaSimpleType) {
                    if (IsValidTypeRedefine(existingObject, item, table)) {
                        return;
                    }
                    code = Res.Sch_DupSimpleType;
                } 
                else if (item is XmlSchemaComplexType) {
                    if (IsValidTypeRedefine(existingObject, item, table)) {
                        return;
                    }
                    code = Res.Sch_DupComplexType;
                }
                else if (item is XmlSchemaGroup) {
                    if (IsValidGroupRedefine(existingObject, item, table)){ //check for redefines
                        return;
                    }
                    code = Res.Sch_DupGroup;
                } 
                else if (item is XmlSchemaNotation) {
                    code = Res.Sch_DupNotation;
                }
                else if (item is XmlSchemaIdentityConstraint) {
                    code = Res.Sch_DupIdentityConstraint;
                }
                else {
                    Debug.Assert(item is XmlSchemaElement);
                }
                SendValidationEvent(code, qname.ToString(), item);
            } 
            else {
                table.Add(qname, item);
            }
        }

        private bool IsValidAttributeGroupRedefine(XmlSchemaObject existingObject, XmlSchemaObject item, XmlSchemaObjectTable table) {
            XmlSchemaAttributeGroup attGroup = item as XmlSchemaAttributeGroup;
            XmlSchemaAttributeGroup existingAttGroup = existingObject as XmlSchemaAttributeGroup;
            if (existingAttGroup == attGroup.Redefined) { //attribute group is the redefinition of existingObject
                if (existingAttGroup.AttributeUses.Count == 0) { //If the existing one is not already compiled, then replace.
                    table.Insert(attGroup.QualifiedName, attGroup); //Update with redefined entry			
                    return true;
                }
            }
            else if (existingAttGroup.Redefined == attGroup) { //Redefined type already exists in the set, original type is added after redefined type, ignore the original type
		return true;
            }
            return false;
        }

        private bool IsValidGroupRedefine(XmlSchemaObject existingObject, XmlSchemaObject item, XmlSchemaObjectTable table) {
            XmlSchemaGroup group = item as XmlSchemaGroup;
            XmlSchemaGroup existingGroup = existingObject as XmlSchemaGroup;
            if (existingGroup == group.Redefined) { //group is the redefinition of existingObject
                if (existingGroup.CanonicalParticle == null) { //If the existing one is not already compiled, then replace.
                    table.Insert(group.QualifiedName, group); //Update with redefined entry			
                    return true;
                }
            }
            else if (existingGroup.Redefined == group) { //Redefined type already exists in the set, original type is added after redefined type, ignore the original type
		return true;
            }
            return false;
        }

        private bool IsValidTypeRedefine(XmlSchemaObject existingObject, XmlSchemaObject item, XmlSchemaObjectTable table) {
            XmlSchemaType schemaType = item as XmlSchemaType;
            XmlSchemaType existingType = existingObject as XmlSchemaType;
            if (existingType == schemaType.Redefined) { //schemaType is the redefinition of existingObject
                if (existingType.ElementDecl == null) { //If the existing one is not already compiled, then replace.
                    table.Insert(schemaType.QualifiedName, schemaType); //Update with redefined entry			
                    return true;
                }
            }
            else if (existingType.Redefined == schemaType) { //Redefined type already exists in the set, original type is added after redefined type, ignore the original type
		return true;
            }
            return false;
        }

        protected void SendValidationEvent(string code, XmlSchemaObject source) {
            SendValidationEvent(new XmlSchemaException(code, source), XmlSeverityType.Error);
        }

        protected void SendValidationEvent(string code, string msg, XmlSchemaObject source) {
            SendValidationEvent(new XmlSchemaException(code, msg, source), XmlSeverityType.Error);
        }

        protected void SendValidationEvent(string code, string msg1, string msg2, XmlSchemaObject source) {
            SendValidationEvent(new XmlSchemaException(code, new string[] { msg1, msg2 }, source), XmlSeverityType.Error);
        }

        protected void SendValidationEvent(string code, string[] args, Exception innerException, XmlSchemaObject source) {
            SendValidationEvent(new XmlSchemaException(code, args, innerException, source.SourceUri, source.LineNumber, source.LinePosition, source), XmlSeverityType.Error);
        }
    
        protected void SendValidationEvent(string code, string msg1, string msg2, string sourceUri, int lineNumber, int linePosition) {
            SendValidationEvent(new XmlSchemaException(code, new string[] { msg1, msg2 }, sourceUri, lineNumber, linePosition), XmlSeverityType.Error);
        }
        
        protected void SendValidationEvent(string code, XmlSchemaObject source, XmlSeverityType severity) {
            SendValidationEvent(new XmlSchemaException(code, source), severity);
        }

        protected void SendValidationEvent(XmlSchemaException e) {
            SendValidationEvent(e, XmlSeverityType.Error);
        }

        protected void SendValidationEvent(string code, string msg, XmlSchemaObject source, XmlSeverityType severity) {
            SendValidationEvent(new XmlSchemaException(code, msg, source), severity);
        }

        protected void SendValidationEvent(XmlSchemaException e, XmlSeverityType severity) {
            if (severity == XmlSeverityType.Error) {
                errorCount ++;
            }
            if (eventHandler != null) {
                eventHandler(null, new ValidationEventArgs(e, severity));
            }
            else if (severity == XmlSeverityType.Error) {
                throw e;
            }
        }

        protected void SendValidationEventNoThrow(XmlSchemaException e, XmlSeverityType severity) {
            if (severity == XmlSeverityType.Error) {
                errorCount ++;
            }
            if (eventHandler != null) {
                eventHandler(null, new ValidationEventArgs(e, severity));
            }
        }
    };

} // namespace System.Xml